The advancement of acoustic metamaterials enables the highly efficient absorption of low-frequency noise with a subwavelength structure thickness, but the complexity of these structures often hinders their large-scale practical applications. Here, we propose a straightforward and compact acoustic metamaterial structure composed of Helmholtz resonators with side slits (HRSS) for low-frequency noise absorption. The introduction of side slits not only simplifies the overall structure but also allows for easy adjustment of acoustic characteristics. By adjusting the depth of the resonator within the slit across 25 distinct units, an absorption coefficient above 0.8 is realized from 470 to 930 Hz. This work demonstrates the extensive low-frequency sound absorption capability of HRSS, providing valuable insights into the design of future practical acoustic materials.
{"title":"A compact acoustic metamaterial based on Helmholtz resonators with side slits for low-frequency sound absorption","authors":"Xingyu Chen, Feiyang Sun, Jing Zhang, Gaorui Chen, Liyue Xu, Li Fan, Liping Cheng, Xiaodong Xu, Yunteng Chen, Jiexin Zhou, Liangping Li, Shaoping Yang","doi":"10.1063/5.0212688","DOIUrl":"https://doi.org/10.1063/5.0212688","url":null,"abstract":"The advancement of acoustic metamaterials enables the highly efficient absorption of low-frequency noise with a subwavelength structure thickness, but the complexity of these structures often hinders their large-scale practical applications. Here, we propose a straightforward and compact acoustic metamaterial structure composed of Helmholtz resonators with side slits (HRSS) for low-frequency noise absorption. The introduction of side slits not only simplifies the overall structure but also allows for easy adjustment of acoustic characteristics. By adjusting the depth of the resonator within the slit across 25 distinct units, an absorption coefficient above 0.8 is realized from 470 to 930 Hz. This work demonstrates the extensive low-frequency sound absorption capability of HRSS, providing valuable insights into the design of future practical acoustic materials.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shufeng Song, Zongyuan Chen, Shengxian Wang, Fengkun Wei, Serguei V. Savilov, Anji Reddy Polu, Pramod K. Singh, Zhaoqin Liu, Ning Hu
Ionogels, which are being considered as quasi-solid electrolytes for energy-storage devices, exhibited technical superiority in terms of nonflammability, negligible vapor pressure, remarkable thermostability, high ionic conductivity, and broad electrochemical stability window. However, their applications in lithium metal batteries (LMBs) have been hindered by several issues: poor compatibility with Li-metal anodes and high-voltage cathodes, high viscosity, and inadequate wettability. Little attention has been paid to ionogel-based low-concentration electrolytes, despite their potential advantages in terms of Li+ mobility, viscosity, electrode wettability, and cost. Here, we demonstrate the surprising capabilities of localized high-concentration ionogel (LHCI) and dilutedly localized high-concentration ionogel (DLHCI) electrolytes, utilizing the non-solvating fluorinated ether 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, to realize high-voltage quasi-solid-state lithium metal batteries (QSLMBs). Notably, the DLHCI electrolyte not only delivers superior ionic conductivity of 3.93 × 10−3 S cm−1 but also provides a high Li plating/stripping Coulombic efficiency exceeding 99%. Moreover, it significantly enhances anodic stability when paired with 4.4 V LiNi0.8Co0.1Mn0.1O2 (NCM811) and 4.8 V LiNi0.5Mn1.5O4 (LNMO). Consequently, substantial improvement in cycling performance of QSLMBs has been realized with the DLHCI electrolyte.
离子凝胶被认为是储能设备的准固体电解质，在不可燃性、可忽略的蒸汽压、显著的热稳定性、高离子电导率和宽电化学稳定性窗口等方面具有技术优势。然而，它们在锂金属电池（LMB）中的应用却受到几个问题的阻碍：与锂金属阳极和高压阴极的兼容性差、粘度高和润湿性不足。基于离子凝胶的低浓度电解质虽然在锂+迁移率、粘度、电极润湿性和成本方面具有潜在优势，但却很少受到关注。在这里，我们展示了局部高浓度离子凝胶（LHCI）和稀释局部高浓度离子凝胶（DLHCI）电解质的惊人能力，它们利用非溶解性氟化醚 1,1,2,2-四氟乙基-2,2,3,3-四氟丙基醚实现了高压准固态锂金属电池（QSLMB）。值得注意的是，DLHCI 电解液不仅离子电导率高达 3.93 × 10-3 S cm-1，而且锂镀层/剥离库仑效率超过 99%。此外，当与 4.4 V LiNi0.8Co0.1Mn0.1O2 (NCM811) 和 4.8 V LiNi0.5Mn1.5O4 (LNMO) 搭配使用时，它还能大大提高阳极稳定性。因此，在使用 DLHCI 电解液时，QSLMB 的循环性能得到了显著改善。
{"title":"Dilutedly localized high-concentration ionogel electrolyte enabling high-voltage quasi-solid-state lithium metal batteries","authors":"Shufeng Song, Zongyuan Chen, Shengxian Wang, Fengkun Wei, Serguei V. Savilov, Anji Reddy Polu, Pramod K. Singh, Zhaoqin Liu, Ning Hu","doi":"10.1063/5.0221854","DOIUrl":"https://doi.org/10.1063/5.0221854","url":null,"abstract":"Ionogels, which are being considered as quasi-solid electrolytes for energy-storage devices, exhibited technical superiority in terms of nonflammability, negligible vapor pressure, remarkable thermostability, high ionic conductivity, and broad electrochemical stability window. However, their applications in lithium metal batteries (LMBs) have been hindered by several issues: poor compatibility with Li-metal anodes and high-voltage cathodes, high viscosity, and inadequate wettability. Little attention has been paid to ionogel-based low-concentration electrolytes, despite their potential advantages in terms of Li+ mobility, viscosity, electrode wettability, and cost. Here, we demonstrate the surprising capabilities of localized high-concentration ionogel (LHCI) and dilutedly localized high-concentration ionogel (DLHCI) electrolytes, utilizing the non-solvating fluorinated ether 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, to realize high-voltage quasi-solid-state lithium metal batteries (QSLMBs). Notably, the DLHCI electrolyte not only delivers superior ionic conductivity of 3.93 × 10−3 S cm−1 but also provides a high Li plating/stripping Coulombic efficiency exceeding 99%. Moreover, it significantly enhances anodic stability when paired with 4.4 V LiNi0.8Co0.1Mn0.1O2 (NCM811) and 4.8 V LiNi0.5Mn1.5O4 (LNMO). Consequently, substantial improvement in cycling performance of QSLMBs has been realized with the DLHCI electrolyte.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
X. B. Yang, H. Zhang, M. M. Tang, H. X. Ma, Y. P. Tai, X. Z. Li
The chiral light field has attracted great attention owing to its interaction with chiral matter. The generation of chiral light fields with rich structures has become crucial as it can expand application scenarios. Herein, we introduce a chiral optical vortex lattice. As a whole, the optical vortex lattice has a chiral intensity distribution, with each spiral arm having sub-vortices (chiral phase). By using an expansion factor to adjust the involute of a circular lattice, this helical optical vortex lattice can be continuously varied from a circular lattice. The chirality of intensity and phase can be controlled independently. Furthermore, the optical tweezers using the lattice demonstrate the capability of sub-vortices to manipulate particle movement, with the chiral intensity determining the trajectory of particle motion. As the lattice possesses both intensity and phase chirality, it may also find potential applications in tasks such as chiral structure microfabrication.
{"title":"Generation of chiral optical vortex lattice for controlled aggregation of particles","authors":"X. B. Yang, H. Zhang, M. M. Tang, H. X. Ma, Y. P. Tai, X. Z. Li","doi":"10.1063/5.0214498","DOIUrl":"https://doi.org/10.1063/5.0214498","url":null,"abstract":"The chiral light field has attracted great attention owing to its interaction with chiral matter. The generation of chiral light fields with rich structures has become crucial as it can expand application scenarios. Herein, we introduce a chiral optical vortex lattice. As a whole, the optical vortex lattice has a chiral intensity distribution, with each spiral arm having sub-vortices (chiral phase). By using an expansion factor to adjust the involute of a circular lattice, this helical optical vortex lattice can be continuously varied from a circular lattice. The chirality of intensity and phase can be controlled independently. Furthermore, the optical tweezers using the lattice demonstrate the capability of sub-vortices to manipulate particle movement, with the chiral intensity determining the trajectory of particle motion. As the lattice possesses both intensity and phase chirality, it may also find potential applications in tasks such as chiral structure microfabrication.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The electrical transport property of layered MoSe2 has a strong response to high pressure by enhancing the inter-layer interaction. However, the narrowed bandgap under high pressure will cause the bipolar effect (i.e., the thermally excited minority carriers contribute to a Seebeck coefficient with the opposite sign to the majority carriers) at high temperatures to degrade the thermoelectric (TE) performance. Hence, suppressing the bipolar effect is important to optimize the TE performance of MoSe2 under high pressure and high temperature (HPHT). In this study, the degradation of TE performance caused by the bipolar effect under HPHT in MoSe2 is investigated. It is found that in MoSe2, the electrical conductivity was improved significantly by pressure; however, the bipolar effect led to a significantly degraded Seebeck coefficient at high temperatures. By injecting massive carriers beforehand, the bipolar effect was suppressed to make a dominant type of p-type charge carries, achieving an increased Seebeck coefficient with increasing temperature, resulting in an improved power factor from 29.3 μW m−1 K−2 in MoSe2 to 285.7 μW m−1 K−2 in Mo0.98Nb0.02Se2 at 5.5 GPa, 1110 K. Combined with the reduced thermal conductivity by point defect scattering on phonons, a maximum ZT value of 0.11 at 5.5 GPa, 1110 K. This work highlights the significance of suppressing the bipolar effect under HPHT for optimizing TE performance in such layered semiconductors.
通过增强层间相互作用，层状 MoSe2 的电气传输特性对高压有很强的响应。然而，高压下带隙变窄会导致高温下的双极效应（即热激发的少数载流子产生与多数载流子符号相反的塞贝克系数），从而降低热电（TE）性能。因此，抑制双极效应对于优化 MoSe2 在高压高温（HPHT）条件下的 TE 性能非常重要。本研究探讨了双极效应导致 MoSe2 在高压高温下 TE 性能下降的问题。研究发现，MoSe2 的电导率在压力作用下得到了显著改善；然而，双极效应导致其在高温下的塞贝克系数明显降低。通过事先注入大量载流子，双极效应被抑制，从而使 p 型电荷载流子占主导地位，实现了塞贝克系数随温度升高而增大，使功率因数从 MoSe2 的 29.3 μW m-1 K-2 提高到 Mo0.02Se2 的 285.7 μW m-1 K-2。在 5.5 GPa、1110 K 条件下，功率因数从 MoSe2 中的 29.3 μW m-1 K-2 提高到 Mo0.98Nb0.02Se2 中的 285.7 μW m-1 K-2；再加上点缺陷对声子的散射降低了热导率，在 5.5 GPa、1110 K 条件下，ZT 值达到最大值 0.11。
{"title":"Enhanced thermoelectric performance of MoSe2 under high pressure and high temperature by suppressing bipolar effect","authors":"Dianzhen Wang, Cun You, Yufei Ge, Fei Wang, Xinglin Wang, Xiao Liang, Qiang Zhou, Qiang Tao, Yanli Chen, Pinwen Zhu","doi":"10.1063/5.0217965","DOIUrl":"https://doi.org/10.1063/5.0217965","url":null,"abstract":"The electrical transport property of layered MoSe2 has a strong response to high pressure by enhancing the inter-layer interaction. However, the narrowed bandgap under high pressure will cause the bipolar effect (i.e., the thermally excited minority carriers contribute to a Seebeck coefficient with the opposite sign to the majority carriers) at high temperatures to degrade the thermoelectric (TE) performance. Hence, suppressing the bipolar effect is important to optimize the TE performance of MoSe2 under high pressure and high temperature (HPHT). In this study, the degradation of TE performance caused by the bipolar effect under HPHT in MoSe2 is investigated. It is found that in MoSe2, the electrical conductivity was improved significantly by pressure; however, the bipolar effect led to a significantly degraded Seebeck coefficient at high temperatures. By injecting massive carriers beforehand, the bipolar effect was suppressed to make a dominant type of p-type charge carries, achieving an increased Seebeck coefficient with increasing temperature, resulting in an improved power factor from 29.3 μW m−1 K−2 in MoSe2 to 285.7 μW m−1 K−2 in Mo0.98Nb0.02Se2 at 5.5 GPa, 1110 K. Combined with the reduced thermal conductivity by point defect scattering on phonons, a maximum ZT value of 0.11 at 5.5 GPa, 1110 K. This work highlights the significance of suppressing the bipolar effect under HPHT for optimizing TE performance in such layered semiconductors.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Weis, M. Lejman, J. Faure, V. Ta Phuoc, L. Cario, D. Boschetto
In this Letter, we investigate coherent phonon dynamics in the incommensurate LaVS3 crystal by femtosecond pump-probe spectroscopy. Two coherent phonon modes are systematically observed in the transient reflectivity, centered at 1.8 and 2.85 THz, respectively, while a third mode centered at 4.5 THz is observed only at high pump fluence. The experimental results obtained at two different polarization configurations as well as a comparison with recent theoretical results allow to assign the two main modes to the interlayer shearing mode and to an intralayer mode, respectively. Two possible assignments are discussed for the third mode, by invoking a possible emergence of nonlinear phonon processes.
{"title":"Coherent phonons in incommensurate LaVS3 crystal","authors":"M. Weis, M. Lejman, J. Faure, V. Ta Phuoc, L. Cario, D. Boschetto","doi":"10.1063/5.0211057","DOIUrl":"https://doi.org/10.1063/5.0211057","url":null,"abstract":"In this Letter, we investigate coherent phonon dynamics in the incommensurate LaVS3 crystal by femtosecond pump-probe spectroscopy. Two coherent phonon modes are systematically observed in the transient reflectivity, centered at 1.8 and 2.85 THz, respectively, while a third mode centered at 4.5 THz is observed only at high pump fluence. The experimental results obtained at two different polarization configurations as well as a comparison with recent theoretical results allow to assign the two main modes to the interlayer shearing mode and to an intralayer mode, respectively. Two possible assignments are discussed for the third mode, by invoking a possible emergence of nonlinear phonon processes.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To reduce the leakage and power consumption of metal–oxide resistive random access memory (RRAM), we propose and fabricate a cold-electrode (CE) RRAM (CE-RRAM) by extending the mechanism of cold-source FETs. First-principles calculations show that the n-Si/TiN composite CE can filter electrons with energy within the Si bandgap, which contribute to leakage current. A n-Si/TiN/HfOx/Pt CE-RRAM with low leakage current and large on/off current ratio was designed and fabricated. Comparative analysis with conventional RRAM demonstrates over a 100-fold reduction in leakage current in a high resistance state and a tenfold improvement in the Ion/Ioff ratio. Additionally, the CE-RRAM effectively suppresses the overshoot effect in terminal I–V characteristics and exhibits good endurance, maintaining a 100 Ion/Ioff ratio after 104 cycles. Furthermore, even after 104 s at 100 °C, the state remains unchanged. Moreover, the CE-RRAM demonstrates its multi-level storage capability.
{"title":"A cold-electrode metal–oxide resistive random access memory","authors":"Jifang Cao, Bing Chen, Zhijiang Wang, Junru Qu, Jiayi Zhao, Rongzong Shen, Xiao Yu, Zhiping Yu, Fei Liu","doi":"10.1063/5.0214593","DOIUrl":"https://doi.org/10.1063/5.0214593","url":null,"abstract":"To reduce the leakage and power consumption of metal–oxide resistive random access memory (RRAM), we propose and fabricate a cold-electrode (CE) RRAM (CE-RRAM) by extending the mechanism of cold-source FETs. First-principles calculations show that the n-Si/TiN composite CE can filter electrons with energy within the Si bandgap, which contribute to leakage current. A n-Si/TiN/HfOx/Pt CE-RRAM with low leakage current and large on/off current ratio was designed and fabricated. Comparative analysis with conventional RRAM demonstrates over a 100-fold reduction in leakage current in a high resistance state and a tenfold improvement in the Ion/Ioff ratio. Additionally, the CE-RRAM effectively suppresses the overshoot effect in terminal I–V characteristics and exhibits good endurance, maintaining a 100 Ion/Ioff ratio after 104 cycles. Furthermore, even after 104 s at 100 °C, the state remains unchanged. Moreover, the CE-RRAM demonstrates its multi-level storage capability.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two-dimensional (2D) ferromagnetic semiconductors with high Curie temperature (TC) and magnetic tunability have garnered significant research interest owing to their immense potential in the realm of spintronic devices. Herein, 2D Ising ferromagnetic semiconductor InMoTe3 monolayer with robust ferromagnetic coupling and TC above room temperature is predicted. Additionally, it has been shown that biaxial strain can notably affect the magnetic interactions and TC of InMoTe3 monolayer. The findings in this study suggest that InMoTe3 monolayer holds promise as a candidate for spintronic device applications, thereby encouraging further theoretical and experimental investigations in this field.
{"title":"Ferromagnetic InMoTe3 monolayer with strain-modulated magnetic interactions and Curie temperature","authors":"Songli Dai, Zean Tian, Guolin Qian, Yutao Liu","doi":"10.1063/5.0208065","DOIUrl":"https://doi.org/10.1063/5.0208065","url":null,"abstract":"Two-dimensional (2D) ferromagnetic semiconductors with high Curie temperature (TC) and magnetic tunability have garnered significant research interest owing to their immense potential in the realm of spintronic devices. Herein, 2D Ising ferromagnetic semiconductor InMoTe3 monolayer with robust ferromagnetic coupling and TC above room temperature is predicted. Additionally, it has been shown that biaxial strain can notably affect the magnetic interactions and TC of InMoTe3 monolayer. The findings in this study suggest that InMoTe3 monolayer holds promise as a candidate for spintronic device applications, thereby encouraging further theoretical and experimental investigations in this field.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The crystal structure of organic semiconductors is an important factor that dominates various electronic properties, including charge transport properties. However, compared with the crystal structures of inorganic semiconductors, those of organic semiconductors are difficult to determine by powder x-ray diffraction (PXRD) analysis. Our proposed machine-learning (neural-network) technique can determine the diffraction peaks buried in noise and make deconvolution of the overlapped peaks of organic semiconductors, resulting in crystal-structure determination by the Rietveld analysis. As a demonstration, we apply the method to a few high-mobility organic semiconductors and confirm that the method is potentially useful for analyzing the crystal structure of organic semiconductors. The present method is also expected to be applicable to the determination of complex crystal structures in addition to organic semiconductors.
有机半导体的晶体结构是主导各种电子特性（包括电荷传输特性）的重要因素。然而，与无机半导体的晶体结构相比，有机半导体的晶体结构很难通过粉末 X 射线衍射（PXRD）分析来确定。我们提出的机器学习（神经网络）技术可以确定埋藏在噪声中的衍射峰，并对有机半导体的重叠峰进行解卷积，从而通过里特维尔德分析法确定晶体结构。作为示范，我们将该方法应用于几种高迁移率有机半导体，并证实该方法可用于分析有机半导体的晶体结构。除有机半导体外，本方法还有望适用于复杂晶体结构的测定。
{"title":"Powder x-ray diffraction analysis with machine learning for organic-semiconductor crystal-structure determination","authors":"Naoyuki Niitsu, Masato Mitani, Hiroyuki Ishii, Nobuhiko Kobayashi, Kenji Hirose, Shun Watanabe, Toshihiro Okamoto, Jun Takeya","doi":"10.1063/5.0208919","DOIUrl":"https://doi.org/10.1063/5.0208919","url":null,"abstract":"The crystal structure of organic semiconductors is an important factor that dominates various electronic properties, including charge transport properties. However, compared with the crystal structures of inorganic semiconductors, those of organic semiconductors are difficult to determine by powder x-ray diffraction (PXRD) analysis. Our proposed machine-learning (neural-network) technique can determine the diffraction peaks buried in noise and make deconvolution of the overlapped peaks of organic semiconductors, resulting in crystal-structure determination by the Rietveld analysis. As a demonstration, we apply the method to a few high-mobility organic semiconductors and confirm that the method is potentially useful for analyzing the crystal structure of organic semiconductors. The present method is also expected to be applicable to the determination of complex crystal structures in addition to organic semiconductors.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heavy rare-earth-based ternary intermetallic compounds with the formula RT2X2 have drawn great interest because of their multiple magnetic transitions and various magnetic structures. Here, anisotropic magnetic behaviors, magnetocaloric effects (MCEs), and magnetostriction effects in single-crystalline GdMn2Ge2 are studied in two different directions. Experiments show a magnetic transition characterized by a sudden decrease in magnetization for μ0H//a and a sharp increase for μ0H//c at Tt. The transition is driven by lower temperatures for μ0H//a, contrasting that for μ0H//c with an increase in the magnetic field. An inverse MCE is observed for μ0H//a with a maximum magnetic entropy change (−ΔSMmax) of −7.4 J kg−1 K−1 (μ0ΔH = 6 T), while a direct MCE is obtained for μ0H//c with an −ΔSMmax of 8.0 J kg−1 K−1 under the same magnetic field change. Moreover, a remarkable field-induced metamagnetic transition and a magnetostriction effect are observed simultaneously at Tt, indicating strong magneto-lattice coupling. The T-μ0H phase diagrams are constructed based on the magnetic properties. The coexistence of direct and inverse MCEs is discussed and is due to the spin-flop of Mn and anisotropic magnetic properties under magnetic fields in different directions.
{"title":"Direct and inverse magnetocaloric effects in magnetostrictive GdMn2Ge2 with field-induced metamagnetic transition","authors":"Canglong Li, Zhaohu Li, Wenqian Yang, Zhaoming Tian, Yang Qiu, Junfan Hua, Shuai Huang","doi":"10.1063/5.0207338","DOIUrl":"https://doi.org/10.1063/5.0207338","url":null,"abstract":"Heavy rare-earth-based ternary intermetallic compounds with the formula RT2X2 have drawn great interest because of their multiple magnetic transitions and various magnetic structures. Here, anisotropic magnetic behaviors, magnetocaloric effects (MCEs), and magnetostriction effects in single-crystalline GdMn2Ge2 are studied in two different directions. Experiments show a magnetic transition characterized by a sudden decrease in magnetization for μ0H//a and a sharp increase for μ0H//c at Tt. The transition is driven by lower temperatures for μ0H//a, contrasting that for μ0H//c with an increase in the magnetic field. An inverse MCE is observed for μ0H//a with a maximum magnetic entropy change (−ΔSMmax) of −7.4 J kg−1 K−1 (μ0ΔH = 6 T), while a direct MCE is obtained for μ0H//c with an −ΔSMmax of 8.0 J kg−1 K−1 under the same magnetic field change. Moreover, a remarkable field-induced metamagnetic transition and a magnetostriction effect are observed simultaneously at Tt, indicating strong magneto-lattice coupling. The T-μ0H phase diagrams are constructed based on the magnetic properties. The coexistence of direct and inverse MCEs is discussed and is due to the spin-flop of Mn and anisotropic magnetic properties under magnetic fields in different directions.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spin pumping has significant implications for spintronics, providing a mechanism to manipulate and transport spins for information processing. Understanding and harnessing spin currents through spin pumping is critical for the development of efficient spintronic devices. The use of a magnetic insulator with low damping enhances the signal-to-noise ratio in crucial experiments such as spin-torque ferromagnetic resonance (FMR) and spin pumping. A magnetic insulator coupled with a heavy metal or quantum material offers a more straightforward model system, especially when investigating spin-charge interconversion processes to greater accuracy. This simplicity arises from the absence of unwanted effects caused by conduction electrons unlike in ferromagnetic metals. Here, we investigate the spin pumping in coupled ferrimagnetic (FiM) Y3Fe5O12 (YIG)/Tm3Fe5O12 (TmIG) bilayers combined with heavy-metal (Pt) using the inverse spin Hall effect. It is observed that magnon transmission occurs at both of the FiMs FMR positions. The enhancement of spin pumping voltage (Vsp) in the FiM garnet heterostructures is observed. The plausible reason might be the interfacial exchange coupling between FiMs. The modulation of Vsp is achieved by tuning the bilayer structure. Further, the spin mixing conductance for these coupled systems is found to be ≈1018 m−2. Our findings describe a coupled FiM system for the investigation of magnon coupling providing opportunities for magnonic devices.
自旋泵对自旋电子学具有重大意义，它为信息处理提供了一种操纵和传输自旋的机制。通过自旋泵了解和利用自旋电流对于开发高效的自旋电子器件至关重要。使用具有低阻尼的磁绝缘体可以提高自旋扭矩铁磁共振（FMR）和自旋泵等关键实验的信噪比。与重金属或量子材料耦合的磁绝缘体提供了一个更简单的模型系统，尤其是在研究自旋电荷相互转换过程时，其精确度更高。与铁磁性金属不同的是，磁绝缘体不存在传导电子引起的不需要的效应，因此具有这种简单性。在这里，我们利用反向自旋霍尔效应研究了与重金属（铂）结合的耦合铁磁性（FiM）Y3Fe5O12 (YIG)/Tm3Fe5O12 (TmIG)双层膜中的自旋泵。研究观察到，磁子传输发生在两个 FiMs 调变位置。在 FiM 石榴石异质结构中观察到自旋泵浦电压（Vsp）的增强。Vsp 的调节是通过调整双层结构实现的。此外，我们还发现这些耦合系统的自旋混合电导率≈1018 m-2。我们的研究结果描述了一种用于研究磁子耦合的耦合 FiM 系统，为磁子器件提供了机会。
{"title":"Enhanced spin pumping in heterostructures of coupled ferrimagnetic garnets","authors":"Anupama Swain, Kshitij Singh Rathore, Pushpendra Gupta, Abhisek Mishra, Yong Heng Lee, Jinho Lim, Axel Hoffmann, Ramanathan Mahendiran, Subhankar Bedanta","doi":"10.1063/5.0201938","DOIUrl":"https://doi.org/10.1063/5.0201938","url":null,"abstract":"Spin pumping has significant implications for spintronics, providing a mechanism to manipulate and transport spins for information processing. Understanding and harnessing spin currents through spin pumping is critical for the development of efficient spintronic devices. The use of a magnetic insulator with low damping enhances the signal-to-noise ratio in crucial experiments such as spin-torque ferromagnetic resonance (FMR) and spin pumping. A magnetic insulator coupled with a heavy metal or quantum material offers a more straightforward model system, especially when investigating spin-charge interconversion processes to greater accuracy. This simplicity arises from the absence of unwanted effects caused by conduction electrons unlike in ferromagnetic metals. Here, we investigate the spin pumping in coupled ferrimagnetic (FiM) Y3Fe5O12 (YIG)/Tm3Fe5O12 (TmIG) bilayers combined with heavy-metal (Pt) using the inverse spin Hall effect. It is observed that magnon transmission occurs at both of the FiMs FMR positions. The enhancement of spin pumping voltage (Vsp) in the FiM garnet heterostructures is observed. The plausible reason might be the interfacial exchange coupling between FiMs. The modulation of Vsp is achieved by tuning the bilayer structure. Further, the spin mixing conductance for these coupled systems is found to be ≈1018 m−2. Our findings describe a coupled FiM system for the investigation of magnon coupling providing opportunities for magnonic devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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